When doing any future work for anyone, it is important to plan out and understand the time and materials needed for that work because it all leads to the overall costs being determined. A good way to plan and establish what the costs of a future job would be is by starting with a list of the materials needed to complete the job, figuring out who and how many workers are needed, seeking out suppliers, etc. Once you know what materials are needed, it can then be calculated how much of each material is needed and where it can be sourced from. The most important factor during the submission of the bid is to ensure its accuracy through the submission to the actual execution. The best way to achieve that is going to be through research and accuracy. Understanding suppliers and sources for materials, quality of materials, comparing and contrasting prices, bulk orders over individual, etc